(a) Field of the Invention
The present invention relates to a liquid crystal display (“LCD”) and a driving method thereof. More particularly, the present invention relates to an LCD having improved transmittance and visibility and a driving method of the LCD.
(b) Description of the Related Art
A liquid crystal display (“LCD”) generally includes an upper panel provided with a common electrode and color filters, a lower panel provided with thin film transistors (“TFTs”) and pixel electrodes, and a liquid crystal (“LC”) layer interposed there between. The pixel electrodes and the common electrode are supplied with different voltages to generate an electric field in the LC layer that determines orientations of LC molecules within the LC layer. Since the orientations of the LC molecules determine the transmittance of incident light, the LCD can display desired images by adjusting the voltage differences between the pixel electrodes and the common electrode, which are also referred to as “field-generating electrodes”.
Among these LCDs, a vertically aligned mode LCD aligns the major axes of the LC molecules vertically with respect to the upper and lower panels in the absence of an electric field, and has a high contrast ratio and wide reference viewing angle. Here, the reference viewing angle is defined as a viewing angle making the contrast ratio equal to 1:10 or as a limit angle for the inversion in luminance between the grays.
The wide viewing angle of the VA mode LCD can be realized by providing cutouts in and protrusions on the field-generating electrodes. Since the cutouts and the protrusions can determine the tilt directions of the LC molecules within the LC layer, the tilt directions can be distributed into several directions by disposing the cutouts and the protrusions in various ways such that the reference viewing angle is widened.